Negotiators at the world summit in Johannesburg have agreed on action aimed at halving the number of people in the world without water and sanitation by 2015.

About 1.1 billion people around the world lack access to adequate drinking water, according to the United Nations - many of them in Africa.

Richard Jolly, a UN adviser on water, said African ministers had agreed that a permanent African Ministers Council on Water (AMCOW) would meet regularly "to find ways of providing water to all Africans".

Mr Jolly announced the deal by the WaterDome, an exhibition site in Johannesburg where water projects are on show during the 10-day World Summit on Sustainable Development.

The council will try to cut the number of people without water

It is estimated that half the people in 25 countries in sub-Saharan Africa will not have access to potable water by 2025 unless action is taken.

Bringing in proper sanitation would significantly reduce diseases such as cholera.

Renewable energy

Governments have also reached agreement on renewable energy sources.

It calls on all countries to "substantially increase" the global share of renewable energy but fails to set any target percentages or dates.

The agreement is a crucial step on the way to developing a common position for a final overall declaration which delegates hope to sign at the end of the summit on Wednesday.

The European Union had been pushing for the share of renewable sources in global energy use to be raised from 14% to 15% by 2010 but the United States and other oil-producing nations opposed this.

A spokesman for the environmentalist group Greenpeace, Steve Sawyer, said the agreement was "worse than we could have imagined".

Discussions are still stuck on a clause in the document referring to the provision of health services.

The US and some of the more conservative countries have opposed any wording which could be seen to support the provision of family planning services - and in particular safe abortion - to poorer women in developing countries.

Call for action

South African President Thabo Mbeki had opened the final phase of the summit by urging leaders to take firm action on poverty and the environment.

After Mr Mbeki spoke, world leaders took to the podium to deliver five-minute addresses.

Zimbabwe's President Robert Mugabe used the opportunity to launch a stinging attack on UK Prime Minister Tony Blair, defending his controversial land reform policies.

To applause from some other African delegates, he told the British leader: "Keep your England and let me keep my Zimbabwe."